How did supermassive black holes form in the early epochs of the universe? More importantly, how did they have enough time to grow as large as they did? The answer requires a very different universe. And back then, conditions were much different than they are now. There was a lot of gas, little dust, no stars, and a plethora of dark matter. Astronomers have spent decades observing early quasars, massive active galaxies powered by huge black holes feeding on surrounding gas. But these galaxies are seen so early in the universe’s history, one starts to wonder how a black hole finds sufficient...
Nebula. Collapse. Protostar. Main Sequence. Red Giant. Planetary Nebula. White Dwarf. This is the cycle of life for a star like our Sun. By observing stars across the galaxy, we see snapshots of different points in a star’s life cycle. It’s the same with people; If you went for a walk in a city and observed people for a day, you would see every single stage of a person’s life: Infant, child, adolescent, youth, adult, middle aged, senior. How would you put them in order if you knew nothing about them? With people you might go up and ask them, but with stars we can...
The Moon has clearly seen some stuff. It’s visibly heavily cratered across it’s surface, which has remained unchanged since it’s surface solidified 4.2 Billion years ago. Think about that – the Moon has been the same, with the exception of cratering, for 4 Billion years. This is a stark contrast to the Earth, whose erosion and tectonic activity cause the crust to change on scales of a few hundred million years. Astronomers have worked hard to learn about the early solar system by looking at the Moon and its cratering patterns. Most of the visible craters on the Moon are...
Our entire universe, from the tiniest atoms, to the structure of our experiential world, to the most massive galaxy clusters and the cosmic web, is dependent on a set of single properties, where small changes to these fundamental numbers would lead to a state where none of it could exist. Understanding these fundamental numbers is the key to unlocking the deepest secrets of the universe and answering the biggest questions of our existence. One of these numbers is the tiny difference in the masses of the proton and neutron. If it varied even a little bit in either direction, we...